Organic light-emitting display device and method of manufacturing the same

ABSTRACT

An organic light-emitting display device and a method of manufacturing the organic light-emitting display device are provided. The organic light-emitting display device includes a plurality of pixels each including: a first region including a light-emitting region for emitting light, a first electrode and an emission layer covering the first electrode being located in the light-emitting region; and a second region including a transmissive region for transmitting external light through the display device. The display device also includes: a third region between the pixels; a first auxiliary layer in the first and third regions; a second electrode on the first auxiliary layer in the first and third regions; a second auxiliary layer covering the second electrode and located in the first and second regions and not in the third region; and a third electrode on the second electrode in the third region.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application is a divisional of U.S. patent application Ser. No.13/738,938, filed Jan. 10, 2013, which claims priority to and thebenefit of Korean Patent Application No. 10-2012-0062347, filed Jun. 11,2012, the entire content of both of which is incorporated herein byreference.

BACKGROUND

1. Field

Aspects of embodiments of the present invention relate to an organiclight-emitting display device and a method of manufacturing the organiclight-emitting display device.

2. Description of the Related Art

Organic light-emitting display devices are self-emitting display devicesthat electrically excite organic compounds to emit light. Organiclight-emitting display devices have drawn attention as next-generationdisplay devices capable of resolving problems that have been pointed outin liquid crystal display devices because organic light-emitting displaydevices may be driven at lower voltages, may be more easily made thin,may have wider viewing angles, and may have faster response speeds whencompared to liquid crystal display devices.

It may be possible to produce a transparent organic light-emittingdisplay device by forming a light-transmitting portion in an area otherthan an area including a thin film transistor or an organiclight-emitting device. This may require performing a patterning processso that a cathode formed using an opaque metal is not formed in thelight-transmitting portion. However, forming an opening pattern in acathode, which may be a common electrode, makes it difficult to use afine metal mask that is often used in a conventional patterning process.In addition, when a common electrode cathode covers all the pixels,wiring resistance may be increased.

SUMMARY

Embodiments of the present invention provide for an organiclight-emitting display device having simplified formation of an openingpattern of a common electrode, and decreased wiring resistance of thecommon electrode. Further embodiments of the present invention providefor a method of manufacturing such an organic light-emitting displaydevice.

According to an exemplary embodiment of the present invention, anorganic light-emitting display device is provided. The display deviceincludes a plurality of pixels each including: a first region includinga light-emitting region for emitting light, a first electrode and anemission layer covering the first electrode being located in thelight-emitting region; and a second region including a transmissiveregion for transmitting external light through the display device. Thedisplay device also includes: a third region between the pixels; a firstauxiliary layer in the first and third regions; a second electrode onthe first auxiliary layer in the first and third regions; a secondauxiliary layer covering the second electrode and located in the firstand second regions and not in the third region; and a third electrode onthe second electrode in the third region.

The second electrode may not be in the second region.

The first auxiliary layer may not be in the second region.

The second electrode may be in the second region. A thickness of thesecond electrode in the second region may be less than a thickness ofthe second electrode in the first region.

The third electrode may be in the second region. A thickness of thethird electrode in the second region may be less than a thickness of thethird electrode in the third region.

The first auxiliary layer may be in the second region.

The display device may further include a third auxiliary layer in thesecond region between the first auxiliary layer and the second auxiliarylayer.

The third auxiliary layer may not be located in the first and thirdregions.

The third auxiliary layer may include at least one selected from thegroup consisting ofN,N′-diphenyl-N,N′-bis(9-phenyl-9H-carbazol-3-yl)biphenyl-4,4′-diamine,N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine,2-(4-(9,10-di(naphthalene-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzo-[D]imidazole),m-MTDATA, α-NPD, and TPD.

The second electrode may be in the second region. A thickness of thesecond electrode in the second region may be less than a thickness ofthe second electrode in the first region.

The third electrode may be in the second region. A thickness of thethird electrode in the second region may be less than a thickness of thethird electrode in the third region.

A thickness of the third electrode may be greater than that of thesecond electrode.

Adhesion of the second electrode in the first and third regions may begreater than adhesion of the second electrode in the second region.

Adhesion of the third electrode in the first and second regions may belower than adhesion of the third electrode in the third region.

The first auxiliary layer may include at least one selected fromtris(8-hydroxy-quinolinato)aluminum (Alq3), di-tungstentetra(hexahydropyrimidopyrimidine), fullerene, lithium fluoride (LiF),9,10-di(naphth-2-yl)anthracene (AND), and 8-hydroxyquinolinolato-lithium(Liq).

The second auxiliary layer may include at least one selected fromN,N′-diphenyl-N,N′-bis(9-phenyl-9H-carbazol-3-yl)biphenyl-4,4′-diamine,N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine,2-(4-(9,10-di(naphthalene-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzo-[D]imidazole),4,4,4-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA),N,N′-bis(1-naphthyl)-N,N′-diphenyl[1,1′-biphenyl]-4,4′-diamine (α-NPD),and 4,4′-Bis[N-(3-methylphenyl)-N-phenylamino]biphenyl (TPD).

The second electrode and the third electrode may include magnesium (Mg).

According to another exemplary embodiment of the present invention, amethod of manufacturing an organic light-emitting display device isprovided. The method includes: defining a plurality of pixels eachincluding a first region including a light-emitting region for emittinglight, and a second region including a transmissive region fortransmitting external light through the display device; defining a thirdregion located between the pixels; forming a first electrode in thelight-emitting region of each pixel; forming an emission layer coveringthe first electrode; forming a first auxiliary layer in the first andthird regions; forming a second electrode by depositing a metal forforming the second electrode on the first auxiliary layer in the firstand third regions; forming a second auxiliary layer covering the secondelectrode and located in the first and second regions and not in thethird region; and forming a third electrode on the second electrode bydepositing a metal for forming the third electrode in the third region.

The forming of the second electrode may include: depositing the metalfor forming the second electrode in the first, second, and thirdregions; and not forming the second electrode in the second region.

The forming of the first auxiliary layer may include patterning thefirst auxiliary layer in the first and third regions and not in thesecond region.

The forming of the second electrode may include: depositing the metalfor forming the second electrode in the first, second, and thirdregions; and forming the second electrode in the second region. Athickness of the second electrode in the second region may be less thana thickness of the second electrode in the first region.

The forming of the third electrode may include: depositing a metal forforming the third electrode in the first, second, and third regions; andforming the third electrode in the second region. A thickness of thethird electrode in the second region may be smaller than a thickness ofthe third electrode in the third region.

The forming of the first auxiliary layer may include forming the firstauxiliary layer in the second region.

The method may further include forming a third auxiliary layer in thesecond region between the first auxiliary layer and the second auxiliarylayer.

The forming of the third auxiliary layer may include patterning thethird auxiliary layer in the second region and not in the first andthird regions.

The third auxiliary layer may include at least one selected fromN,N′-diphenyl-N,N′-bis(9-phenyl-9H-carbazol-3-yl)biphenyl-4,4′-diamine,N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine,2-(4-(9,10-di(naphthalene-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzo-[D]imidazole),m-MTDATA, α-NPD, and TPD.

The forming of the second electrode may include: depositing the metalfor forming the second electrode in the first, second, and thirdregions; and forming the second electrode in the second region. Athickness of the second electrode in the second region may be less thana thickness of the second electrode in the first region.

The forming of the third electrode may include: depositing the metal forforming the third electrode in the first, second, and third regions; andforming the third electrode in the second region. A thickness of thethird electrode in the second region may be less than a thickness of thethird electrode in the third region.

The third electrode may be formed thicker than the second electrode.

Adhesion of the second electrode in the second region may be lower thanadhesion of the second electrode in the first and third regions.

Adhesion of the third electrode in the first and second regions may belower than adhesion of the third electrode in the third region.

The first auxiliary layer may include at least one selected fromtris(8-hydroxy-quinolinato)aluminum (Alq3), di-tungstentetra(hexahydropyrimidopyrimidine), fullerene, lithium fluoride (LiF),9,10-di(naphth-2-yl)anthracene (AND), and 8-hydroxyquinolinolato-lithium(Liq).

The second auxiliary layer may include at least one selected fromN,N′-diphenyl-N,N′-bis(9-phenyl-9H-carbazol-3-yl)biphenyl-4,4′-diamine,N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine,2-(4-(9,10-di(naphthalene-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzo-[D]imidazole),4,4,4-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA),N,N′-bis(1-naphthyl)-N,N′-diphenyl[1,1′-biphenyl]-4,4′-diamine (α-NPD),and 4,4′-Bis[N-(3-methylphenyl)-N-phenylamino]biphenyl (TPD).

The metal for forming the second electrode and the metal for forming thethird electrode may include magnesium (Mg).

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and aspects of the present invention willbecome more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings in which:

FIG. 1 is a schematic cross-sectional view of an organic light-emittingdisplay device according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of an organic light-emittingdisplay device according to another embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of an organic light-emittingdisplay device according to another embodiment of the present invention;

FIG. 4 is a detailed cross-sectional view of an organic light-emittingdisplay device according to an embodiment of the present invention;

FIG. 5 is a detailed cross-sectional view of an organic light-emittingdisplay device according to another embodiment of the present invention;

FIG. 6 is a plan view showing adjacent pixels of an organiclight-emitting display device according to an embodiment of the presentinvention;

FIG. 7 is a cross-sectional view taken along line I-I of FIG. 6according to an embodiment of the present invention;

FIG. 8 is a cross-sectional view taken along line I-I of FIG. 6according to another embodiment of the present invention;

FIG. 9 is a cross-sectional view taken along line I-I of FIG. 6according to another embodiment of the present invention;

FIG. 10 is a cross-sectional view taken along line I-I of FIG. 6according to another embodiment of the present invention; and

FIG. 11 is a plan view showing adjacent pixels of an organiclight-emitting display device according to another embodiment of thepresent invention.

DETAILED DESCRIPTION

Now, exemplary embodiments according to the present invention will bedescribed in detail with reference to the accompanying drawings. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items. Expressions such as “at least oneof,” when preceding a list of elements, modify the entire list ofelements and do not modify the individual elements of the list.

FIG. 1 is a schematic cross-sectional view of an organic light-emittingdisplay device according to an embodiment of the present invention.

Referring to FIG. 1, the organic light-emitting display device includesa substrate 1 and a display unit 2 formed on the substrate 1. In theorganic light-emitting display device, external light penetrates thesubstrate 1 and the display unit 2. For example, external light entersone side of the organic light-emitting display device, transmits throughthe display unit 2 and the substrate 1, and exits another side of theorganic light-emitting display device. That is, the display unit 2 isformed to transmit external light (e.g., is transparent), as describedin more detail below. As depicted in FIG. 1, the display unit 2 isformed so that a user viewing an image displayed on the organiclight-emitting display device may also view an external lighttransmission (for example, a scene behind the organic light-emittingdisplay device) transmitted through the substrate 1 and the display unit2.

FIG. 1 shows a first pixel P1 and a second pixel P2 that are disposed(for example, located) adjacent to each other in the organiclight-emitting display device. Each of the first and second pixels P1and P2 includes a first region 31 and a second region 32. An image isdisplayed by the display unit 2 through the first region 31 whileexternal light penetrates (i.e., transmits through) the second region32. In other words, both the first and second pixels P1 and P2 includethe first region 31 to display an image and the second region 32 throughwhich external light penetrates and thus, a user may see an externalscene (i.e., behind the organic light-emitting display device) throughthe second region 32 in addition to or in place of when the user seesthe image displayed in the first region 31.

In this regard, transmittance of the external light may be significantlyincreased by not forming devices such as a thin film transistor, acapacitor, or an organic light-emitting device in the second region 32.That is, by forming devices such as thin film transistors, capacitors,and organic light-emitting devices in the first region 31 and not in thesecond region 32, distortion or other degradation of the transmittedexternal light due to interference by such devices may be reduced orprevented as much as possible.

Although FIG. 1 shows a bottom emission-type light-emitting displaydevice in which an image of the display unit 2 is displayed toward thesubstrate 1, the present invention is not limited thereto. As shown inFIG. 2, embodiments of the present invention may be used in a topemission-type light-emitting display device in which the image of thedisplay unit 2 is displayed away from the substrate 1. In addition, asshown in FIG. 3, embodiments of the present invention may be used in atwo-sided light-emitting display device in which the image of thedisplay unit 2 is displayed both toward and away from the substrate 1.

The above-described embodiments of the organic light-emitting displaydevice may be embodied in further detail as shown in FIG. 4 and/or FIG.5.

Referring to FIG. 4, the display unit 2 includes an organiclight-emitting unit 21 formed on the substrate 1 and a sealing substrate23 for sealing the organic light-emitting unit 21. The sealing substrate23 is formed of a transparent member to display an image from theorganic light-emitting unit 21 and reduces or prevents external air andmoisture from entering the organic light-emitting unit 21. Edges of thesubstrate 1 and the sealing substrate 23 are coupled to each other via asealing material 24 to seal a space 25 between the substrate 1 and thesealing substrate 23. A moisture absorbent, a filling material, or thelike may be located in the space 25.

As shown in FIG. 5, a sealing film 26 formed thin, instead of thesealing substrate 23, may be formed on the organic light-emitting unit21 to protect the organic light-emitting unit 21 against external air ormoisture. The sealing film 26 may have a structure in which a filmformed of an inorganic material, such as silicon oxide or siliconnitride, and a film formed of an organic material, such as epoxy orpolyimide, are alternately formed, but the present invention is notlimited thereto. That is, any transparent thin film having a sealingstructure may be used as the sealing film 26.

FIG. 6 is a plan view showing pixels P of an organic light-emittingdisplay device according to an embodiment of the present invention. FIG.7 is a cross-sectional view taken along line I-I of FIG. 6 according toan embodiment of the present invention. Each pixel P may include a redpixel Pr, a green pixel Pg, and a blue pixel Pb that are disposedadjacent to one another.

Each of the red pixel Pr, the green pixel Pg, and the blue pixel Pbincludes a circuit region 311 and a light-emitting region 312 in thefirst region 31. In the embodiment of FIGS. 6-7, the circuit region 311and the light-emitting region 312 are disposed to overlap with eachother. The light-emitting region 312 includes a first electrode 221 thatmay be disposed to overlap with the circuit region 311.

The second region 32, including a transmissive region for transmittingexternal light, is disposed adjacent to the first region 31. Althoughthe transmissive region corresponds to the second region 32 in FIG. 6,the present invention is not limited thereto. In addition, in FIG. 6,the second region 32 is formed wider than the first region 31 to includethe transmissive region.

The second regions 32 may be independently formed in the red, green, andblue pixels Pr, Pg, and Pb or may be formed to be connected to oneanother across the red, green, and blue pixels Pr, Pg, and Pb. In otherwords, one pixel P includes the red pixel Pr, the green pixel Pg, andthe blue pixel Pb. In this regard, one pixel P may include the secondregion 32 and thus, the second region 32 may be formed across the redpixel Pr, the green pixel Pg, and the blue pixel Pb. In this case, sincean area of the second region 32 for transmitting external light may beextended, transmittance of the entire display unit 2 may be increased.

A second electrode 222 is disposed in the first region 31. As with thesecond region 32, one pixel P may include the second electrode 222 andthus, the second electrode may be formed across the red pixel Pr, thegreen pixel Pg, and the blue pixel Pb.

A third region 33 is located between the pixels P. A third electrode 223is located in the third region 33. At least one wiring line 331 may belocated in the third region 33, as shown in FIG. 7. The wiring line 331may be electrically connected to a pixel circuit unit to be describedbelow.

Each circuit region 311 includes a pixel circuit unit including a thinfilm transistor TR, as shown in FIG. 7. However, the present inventionis not limited thereto, and the pixel circuit unit may further include aplurality of thin film transistors TR and one or a plurality of storagecapacitors. The pixel circuit unit may further include a plurality ofwiring lines, such as scan lines, data lines, and Vdd lines, connectedto the thin film transistors TR and the storage capacitors.

Each light-emitting region 312 may include an organic light-emittingdiode EL that is a luminous element. The organic light-emitting diode ELis electrically connected to the thin film transistor TR of the pixelcircuit unit.

A buffer layer 211 is formed on the substrate 1, and the pixel circuitunit, including the thin film transistor TR, is formed on the bufferlayer 211. A semiconductor active layer 212 is formed on the bufferlayer 211. The buffer layer 211 is formed of a transparent insulatingmaterial, and also may be formed of any of various other materialscapable of reducing or preventing penetration of impurity substances andof planarizing a surface of the substrate 1. For example, the bufferlayer 211 may be formed of an inorganic material such as silicon oxide,silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride,titanium oxide, or titanium nitride, an organic material such aspolyimide, polyester, or acryl, or a stack of inorganic and organicmaterials. In other embodiments, the buffer layer 211 may not be formed.

The semiconductor active layer 212 may be formed of polycrystallinesilicon. However, the present invention is not limited thereto, and thesemiconductor active layer 212 may be formed of an oxide semiconductor.For example, the semiconductor active layer 212 may be a G-I-Z—O layer[(In₂O₃)a(Ga₂O₃)b(ZnO)c layer] (a, b, and c are real numbers satisfyingconditions a≧0, b≧0, and c>0, respectively). When the semiconductoractive layer 212 is formed of an oxide semiconductor, lighttransmittance in the circuit region 311 of the first region 31 mayfurther be increased and thus, transmittance of external light of theentire display unit 2 may be increased.

A gate insulating layer 213 is formed on the buffer layer 211 to coverthe semiconductor active layer 212. A gate electrode 214 is formed onthe gate insulating layer 213. An insulating interlayer 215 is formed onthe gate insulating layer 213 to cover the gate electrode 214. A sourceelectrode 216 and a drain electrode 217 are formed on the insulatinginterlayer 215 to contact the semiconductor active layer 212 via contactholes. In other embodiments, the structure of the thin film transistorTR is not limited thereto, and a thin film transistor TR having any ofvarious other structures may be used.

A first insulating layer 218 is formed to cover the thin film transistorTR. The first insulating layer 218 may be an insulating layer having asingle-layered or multi-layered structure with a planarized top surface.The first insulating layer 218 may be formed of an inorganic materialand/or an organic material.

The first electrode 221 of the organic light-emitting diode EL iselectrically connected to the thin film transistor TR and is formed onthe first insulating layer 218, as shown in FIG. 7. The first electrode221 is formed into an island shape that is independently formed in eachpixel.

A second insulating layer 219 is formed on the first insulating layer218 to cover an edge of the first electrode 221. An opening 219 a isformed in the second insulating layer 219 to expose a center portion,other than the edge, of the first electrode 221. The second insulatinglayer 219 may be formed of an organic material such as acryl orpolyimide.

An EL layer 220 is formed on the first electrode 221 exposed by theopening 219 a. The second electrode 222 is formed to cover the EL layer220, thereby completing the formation of the organic light-emittingdiode EL. The EL layer 220 may be a low-molecular organic layer or apolymer organic layer. When the EL layer 220 is a low-molecular organiclayer, a hole injection layer (HIL), a hole transport layer (HTL), anemission layer (EML), an electron transport layer (ETL), and an electroninjection layer (EIL) may be stacked as a multi-layered structure. Theselow-molecular organic layers may be formed by using a vacuum evaporationmethod.

The EML is formed in each of the red, green, and blue pixels. The otherlayers, for example, the HIL, the HTL, the ETL, the EIL, etc., arecommon layers and may be commonly used and/or formed in the red, green,and blue pixels. Although the EL layer 220 is patterned to be locatedonly in the first region 31 in FIG. 7, the present invention is notlimited thereto. In addition, although not shown in the drawing, thecommon layers such as the HIL, the HTL, the ETL, and the EIL may belocated in the second region 32 and/or the third region 33, and this mayalso be applied to all subsequently described embodiments.

The HIL may be formed of phthalocyanine compounds such as copperphthalocyanine (CuPc), or TCTA,4,4,4-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), orm-MTDAPB, which is a starburst amine-based material. The HTL may beformed of, for example,4,4′-Bis[N-(3-methylphenyl)-N-phenylamino]biphenyl (TPD),N,N′-bis(1-naphthyl)-N,N′-diphenyl[1,1′-biphenyl]-4,4′-diamine (α-NPD),or the like. The EIL may be formed of, for example, LiF, NaCl, CsF,Li₂O, BaO, Liq, or the like. The ETL may be formed of, for example,Alq3.

The EML may include a host material and a dopant material. Examples ofthe host material may include tris(8-hydroxy-quinolinato)aluminum(Alq3), 9,10-di(naphth-2-yl)anthracene (AND),2-tert-butyl-9,10-di(naphth-2-yl)anthracene (TBADN),4,4′-bis(2,2-diphenyl-ethene-1-yl)-4,4′-dimethylphenyl (DPVBi),4,4′-bis(2,2-di(4-methyphenyl-ethene-1-yl)-biphenyl (p-DMDPVBi), etc.Examples of the dopant material may include4,4′-bis[4-(di-p-tolylamino)styryl]biphenyl (DPAVBi),9,10-di(naph-2-tyl)anthracene (ADN),2-tert-butyl-9,10-di(naph-2-tyl)anthracene (TBADN), etc.

The first electrode 221 may serve as an anode and the second electrode222 may serve as a cathode, or vice-versa. When the first electrode 221serves as an anode, the first electrode 221 may be formed of a high-workfunction material, for example, indium tin oxide (ITO), indium zincoxide (IZO), zinc oxide (ZnO), In₂O₃, etc. In FIG. 7, if the organiclight-emitting display device is a top emission-type light-emittingdisplay device in which an image is displayed away from the substrate 1,the first electrode 221 may further include a reflection layer (notshown) formed of silver (Ag), magnesium (Mg), aluminum (Al), platinum(Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium(Ir), chromium (Cr), lithium (Li), ytterbium (Yb), cobalt (Co), samarium(Sm), or calcium (Ca).

When the second electrode 222 serves as a cathode, the second electrode222 may be formed of a metal such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir,Cr, Li, Yb, Co, Sm, or Ca. In FIG. 7, if the organic light-emittingdisplay device is a bottom emission-type light-emitting display devicein which an image is displayed toward the substrate 1, the secondelectrode 222 may be formed of a material having light transmittance.For this, the second electrode 222 may be formed as a thin film using Mgand/or a Mg alloy. Unlike the first electrode 221, the second electrode222 may be formed as a common electrode to apply a common voltage to allthe pixels P.

When the second electrode 222 is a common electrode that applies acommon voltage to all the pixels P, a surface resistance of the secondelectrode 222 is increased and thus, a voltage drop may occur. Toaddress this problem, the third electrode 223 may further be formed tobe electrically connected to the second electrode 222. The thirdelectrode 223 may be formed of a metal such as Ag, Mg, Al, Pt, Pd, Au,Ni, Nd, Ir, Cr, Li, Yb, Co, Sm, or Ca. In addition, the third electrode223 may be formed of the same material used for forming the secondelectrode 222.

According to the embodiment shown in FIG. 7, a first auxiliary layer 231is formed on the EL layer 220 and the second insulating layer 219 beforeforming the second electrode 222. The first auxiliary layer 231 isformed only in the first region 31 and the third region 33 and not inthe second region 32, which is a region for transmitting light, bydeposition using a mask (not shown).

The first auxiliary layer 231 may be formed of a material that may bondwell to the metal for forming the second electrode 222 (in particular,Mg and/or a Mg alloy) formed on the first auxiliary layer 231. Forexample, the first auxiliary layer 231 may include Alq3, di-tungstentetra(hexahydropyrimidopyrimidine), fullerene, lithium fluoride (LiF),9,10-di 2-naphthyl)anthracene (ADN), or 8-hydroxyquinolinolato-lithium(Liq). The first auxiliary layer 231 is patterned to be formed only inthe first region 31 and the third region 33 and not in the second region32, and then is formed on the EL layer 220 (in the first region 31) andthe second insulating layer 219 (in the third region 33), and then thesecond electrode 222 is formed.

The second electrode 222 may be formed by commonly depositing a metalfor forming the second electrode 222 on all the pixels P including thefirst to third regions 31 to 33 by using an open mask. In this regard,as described above, the second electrode 222 is formed into a thin filmto be a semi-permeable reflection film (e.g., a semi-transparent andsemi-reflective film). As such, if the metal for forming the secondelectrode 222 is commonly deposited on all the pixels P by using an openmask, the metal for forming the second electrode 222 is deposited on thefirst auxiliary layer 231 (e.g., in the first and third regions 31 and33) and the second insulating layer 219 (e.g., in the second region 32).Also, if the EL layer 220 includes a common layer, the metal for formingthe second electrode 222 may be deposited on the common layerconstituting the EL layer 220, in particular, an EIL (not shown),instead of being deposited on the second insulating layer 219.

In this regard, the second electrode 222 may be formed only on the firstauxiliary layer 231 instead of being formed on the second insulatinglayer 219 exposed in the second region 32 and/or on the common layerconstituting the EL layer 220, as shown in FIG. 7, by allowing the metalfor forming the second electrode 222 to be deposited favorably on thefirst auxiliary layer 231 and to be deposited unfavorably on the secondinsulating layer 219 and/or the common layer. In other words, sinceadhesion of the second electrode 222 with respect to the first and thirdregions 31 and 33 is greater than adhesion of the second electrode 222with respect to the second region 32, and since the second electrode 222is formed into a thin film, the second electrode 222 is formed only inthe first region 31 and the third region 33 and not in the second region32.

Thus, the second electrode 222 may be easily patterned without using aseparate mask for patterning. For this, the second insulating layer 219and/or the common layer may be formed of a material having low adhesionwith respect to the metal for forming the second electrode 222, comparedto that of the first auxiliary layer 231. For example, the secondinsulating layer 219 may be formed of acryl, and the common layer, inparticular, the EIL, may be formed of Liq. The second electrode 222formed in the above-described way is located only in the first region 31and the third region 33 and not in the second region 32.

Next, a second auxiliary layer 232 is formed in the first region 31 andthe second region 32. The second auxiliary layer 232 is formed on thesecond electrode 222 in the first region 31 and is formed on the secondinsulating layer 219 in the second region 32 or on the common layerconstituting the EL layer 220. The second auxiliary layer 232 may bepatterned not to be formed in the third region 33.

The second auxiliary layer 232 may be formed of a material that may notbond well to the metal for forming the third electrode 223 (inparticular, Mg and/or a Mg alloy) formed on the second electrode 222.For example, the second auxiliary layer 232 may be formed of a materialincludingN,N′-diphenyl-N,N′-bis(9-phenyl-9H-carbazol-3-yl)biphenyl-4,4′-diamine,N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine,2-(4-(9,10-di(naphthalene-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzo-[D]imidazole),m-MTDATA, α-NPD, or TPD.

The second auxiliary layer 232 serves as a mask when forming the thirdelectrode 223. In other words, when the metal for forming the thirdelectrode 223 is commonly deposited on the first to third regions 31 to33 by using an open mask after forming the second auxiliary layer 232,the third electrode 223 may not be favorably deposited in the firstregion 31 and the second region 32 and may be formed only in the thirdregion 33 because the second auxiliary layer 232 is formed in the firstregion 31 and the second region 32. The third electrode 223 is formedthicker than the second electrode 222, and thus, a voltage drop may bereduced or prevented from occurring in the second electrode 222 forapplying a common voltage.

The above-described embodiment has process benefits because the secondelectrode 222 and the third electrode 223 formed of a metal may bepatterned without using a separate mask. In addition, transmittance ofan entire panel may be improved by not forming the second electrode 222and the third electrode 223 in the second region 32 including atransmissive region.

FIG. 8 is a cross-sectional view taken along line I-I of FIG. 7according to another embodiment of the present invention.

Even though the first auxiliary layer 231 is formed of a material thatmay bond well to the metal for forming the second electrode 222 (inparticular, Mg and/or a Mg alloy) formed on the first auxiliary layer231, a small amount of metal may be deposited even in a region where thefirst auxiliary layer 231 is not formed. Thus, when the first auxiliarylayer 231 is formed only in the first region 31 and the third region 33and not in the second region 32, if a metal for forming the secondelectrode 222 is deposited in the first region 31 to the third region 33by using an open mask as in the embodiment shown in FIG. 7, the secondelectrode 222 may be formed in the first region 31 to the third region33 as shown in FIG. 8. In this regard, a thickness t2 of a portion 222 bof the second electrode 222 located in the second region 32 may besmaller than a thickness t1 of a portion 222 a of the second electrode222 located in the first region 31 and the third region 33. For example,the thickness t2 of the second electrode 222 in the second region 32 maybe less than the thickness t1 of the second electrode 222 in the firstand third regions 31 and 33.

In addition, even though the second auxiliary layer 232 is formed of amaterial that may not bond well to a metal for forming the thirdelectrode 223 (in particular, Mg and/or a Mg alloy) formed on the secondauxiliary layer 232, a small amount of metal may be deposited on thesecond auxiliary layer 232. Thus, when the second auxiliary layer 232 isformed only in the first region 31 and the second region 32 and not inthe third region 33, if a metal for forming the third electrode 223 isdeposited in the first region 31 to the third region 33 by using an openmask as in the embodiment shown in FIG. 7, the third electrode 223 maybe formed in the first region 31 to the third region 33 as shown in FIG.8. In this regard, a thickness t4 of a portion 223 b of the thirdelectrode 223 located in the first region 31 and the second region 32may be smaller (for example, much smaller) than a thickness t3 of aportion 223 a of the third electrode 223 located in the third region 33.

As such, in the embodiment shown in FIG. 8, the portion 222 b of thesecond electrode 222 formed of a metal and the portion 223 b of thethird electrode 223 are located in the second region 32, which is atransmissive region. However, in this case, since the portion 222 b ofthe second electrode 222 and the portion 223 b of the third electrode223 are formed relatively thin, transmittance of external light throughthe second region 32 may not be greatly decreased.

FIG. 9 is a cross-sectional view taken along line I-I of FIG. 6according to another embodiment of the present invention.

The embodiment shown in FIG. 9 is the same as that shown in FIG. 7and/or FIG. 8 up to the process of forming of the EL layer 220. At thatpoint, the first auxiliary layer 231 is deposited on the EL layer 220across the first region 31 to the third region 33. Then, a thirdauxiliary layer 233 is formed on the first auxiliary layer 231. In thisregard, the third auxiliary layer 233 may be located only in the secondregion 32 by forming the third auxiliary layer 233 using a patterningmask.

The third auxiliary layer 233 may be formed of a material having thesame characteristics as the second auxiliary layer 232. In other words,the third auxiliary layer 233 may be formed of a material that may notbond well to the metal for forming the second electrode 222 (inparticular, Mg and/or a Mg alloy) formed on the first auxiliary layer231.

The metal for forming the second electrode 222 is deposited across thefirst region 31 to the third region 33 by using an open mask afterforming the third auxiliary layer 233. Thus, the metal for forming thesecond electrode 222 is deposited on the first auxiliary layer 231 inthe first region 31 and the third region 33 and is deposited on thethird auxiliary layer 233 in the second region 32. In this regard, sinceadhesion between the first auxiliary layer 231 and the metal for formingthe second electrode 222 is favorable and adhesion between the thirdauxiliary layer 233 and the metal for forming the second electrode 222is unfavorable, the second electrode 222 is formed only in the firstregion 31 and the third region 33 and not in the second region 32.

Next, the second auxiliary layer 232 is formed on the second electrode222 and the third auxiliary layer 233. In this regard, the secondauxiliary layer 232 may be formed only in the first region 31 and thesecond region 32 and not in the third region 33 by forming the secondauxiliary layer 232 using a patterning mask.

Next, a metal for forming the third electrode 224 is deposited acrossthe first region 31 to the third region 33 by using an open mask. Thus,the metal for forming the third electrode 224 is deposited on the secondauxiliary layer 232 in the first region 31 and the second region 32 andon the second electrode 222 in the third region 33. In this regard,since adhesion between the second auxiliary layer 232 and the metal forforming the third electrode 224 is unfavorable, the third electrode 224is formed only in the third region 33 and not in the first region 31 andthe second region 32.

The above-described embodiment has process benefits because the secondelectrode 222 and the third electrode 224 formed of a metal may bepatterned without using a separate mask, and transmittance of an entirepanel may be improved by not forming the second electrode 222 and thethird electrode 224 in the second region 32 including a transmissiveregion.

FIG. 10 is a cross-sectional view taken along line I-I of FIG. 9according to another embodiment of the present invention.

Similar to the second auxiliary layer 232, even though the thirdauxiliary layer 233 is formed of a material that may not bond well to ametal, in particular, to Mg and/or a Mg alloy, a small amount of metalmay be deposited on the third auxiliary layer 233. Thus, when the thirdauxiliary layer 233 is formed only in the second region 32 and not inthe first region 31 and the third region 33, if a metal for forming thesecond electrode 222 is deposited in the first region 31 to the thirdregion 33 by using an open mask as in the embodiment shown in FIG. 9,the second electrode 222 may be formed in the first region 31 to thethird region 33 as shown in FIG. 10. In this regard, the thickness t2 ofthe portion 222 b of the second electrode 222 located in the secondregion 32 may be smaller (for example, significantly smaller) than thethickness t1 of the portion 222 a of the second electrode 222 located inthe first region 31 and the third region 33.

In addition, as described above, a small amount of metal may bedeposited on the second auxiliary layer 232. Thus, when the secondauxiliary layer 232 is formed only in the first region 31 and the secondregion 32 and not in the third region 33, if a metal for forming thethird electrode 223 is deposited in the first region 31 to the thirdregion 33 by using an open mask as in the embodiment shown in FIG. 9,the third electrode 223 may be formed in the first region 31 to thethird region 33 as shown in FIG. 10. In this regard, the thickness t4 ofthe portion 223 b of the third electrode 223 located in the first region31 and the second region 32 may be smaller (for example, significantlysmaller) than the thickness t3 of the portion 223 a of the thirdelectrode 223 located in the third region 33.

As such, in the embodiment shown in FIG. 10, the portion 222 b of thesecond electrode 222 formed of a metal and the portion 223 b of thethird electrode 223 are located in the second region 32, which is atransmissive region. However, in this case, since the portion 222 b ofthe second electrode 222 and the portion 223 b of the third electrode223 are formed relatively thin, transmittance of external light throughthe second region 32 may not be greatly decreased.

In the embodiments shown in FIGS. 6 to 10, since the circuit region 311overlaps with the light-emitting region 312, the embodiments shown inFIGS. 6 to 10 may be more appropriate for a top emission-typelight-emitting display device in which an image is displayed away fromthe substrate 1. In this case, since the circuit region 311 is coveredby the light-emitting region 312, a decrease in transmittance ofexternal light due to the circuit region 311 may be suppressed, andalso, a decrease in luminance efficiency of the light-emitting region312 due to the circuit region 311 may be suppressed.

FIG. 11 is a plan view showing adjacent pixels of an organiclight-emitting display device according to another embodiment of thepresent invention. In FIG. 11, the circuit region 311 does not overlapwith the light-emitting region 312 and the first electrode 221. Theorganic light-emitting display device having a structure shown in FIG.11 may be appropriate even when the organic light-emitting displaydevice is a bottom emission-type light-emitting display device in whichan image emitted from the light-emitting region 312 is displayed towardthe substrate 1.

In the organic light-emitting display device having a structure shown inFIG. 11, the light-emitting region 312 is not influenced by the circuitregion 311 and thus, luminance efficiency of the light-emitting region312 may be prevented from being decreased (or any such decreasing can bereduced). However, although not shown in FIG. 11, the circuit region 311of the first region 31 may at least partially overlap with the thirdregion 33 in the embodiment shown in FIG. 11. Thus, the third electrode223 formed in the third region 33 may overlap with the circuit region311. An area of the second auxiliary layer 232 (see FIGS. 7-10) servingas a mask for forming the third electrode 223 may be adjusted tocorrespond to an area where the third electrode 223 is formed.

In the above-described embodiments, the light-emitting display device ispatterned in such a way that only the second electrode 222 has anopening in the second region 32, but the present invention is notlimited thereto. The light-emitting display device may be patterned insuch a way that at least a part of at least one insulating layer fromamong insulating layers located in the second region 32 has an opening,and thus, transmittance of external light in the second region 32 mayfurther be increased.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims and theirequivalents.

What is claimed is:
 1. A method of manufacturing an organiclight-emitting display device, the method comprising: defining aplurality of pixels each comprising a first region comprising alight-emitting region for emitting light, and a second region comprisinga transmissive region for transmitting external light through thedisplay device; defining a third region located between the pixels;forming a first electrode in the light-emitting region of each pixel;forming an emission layer covering the first electrode; forming a firstauxiliary layer in the first and third regions; forming a secondelectrode by depositing a metal for forming the second electrode on thefirst auxiliary layer in the first and third regions; forming a secondauxiliary layer covering the second electrode in the first region, thesecond auxiliary layer further being located in the second region butnot in the third region; and forming a third electrode on the secondelectrode by depositing a metal for forming the third electrode in thethird region.
 2. The method of claim 1, wherein the forming of thesecond electrode comprises: depositing the metal for forming the secondelectrode in the first, second, and third regions; and not forming thesecond electrode in the second region.
 3. The method of claim 1, whereinthe forming of the first auxiliary layer comprises patterning the firstauxiliary layer in the first and third regions and not in the secondregion.
 4. The method of claim 3, wherein the forming of the secondelectrode comprises: depositing the metal for forming the secondelectrode in the first, second, and third regions; and forming thesecond electrode in the second region, wherein a thickness of the secondelectrode in the second region is less than a thickness of the secondelectrode in the first region.
 5. The method of claim 3, wherein theforming of the third electrode comprises: depositing a metal for formingthe third electrode in the first, second, and third regions; and formingthe third electrode in the second region, wherein a thickness of thethird electrode in the second region is smaller than a thickness of thethird electrode in the third region.
 6. The method of claim 1, whereinthe forming of the first auxiliary layer comprises forming the firstauxiliary layer in the second region.
 7. The method of claim 6, furthercomprising forming a third auxiliary layer in the second region betweenthe first auxiliary layer and the second auxiliary layer.
 8. The methodof claim 7, wherein the forming of the third auxiliary layer comprisespatterning the third auxiliary layer in the second region and not in thefirst and third regions.
 9. The method of claim 7, wherein the thirdauxiliary layer comprises at least one selected from the groupconsisting ofN,N′-diphenyl-N,N′-bis(9-phenyl-9H-carbazol-3-yl)biphenyl-4,4′-diamine,N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine,2-(4-(9,10-di(naphthalene-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzo-[D]imidazole),m-MTDATA, α-NPD, and TPD.
 10. The method of claim 6, wherein the formingof the second electrode comprises: depositing the metal for forming thesecond electrode in the first, second, and third regions; and formingthe second electrode in the second region, and wherein a thickness ofthe second electrode in the second region is less than a thickness ofthe second electrode in the first region.
 11. The method of claim 6,wherein the forming of the third electrode comprises: depositing themetal for forming the third electrode in the first, second, and thirdregions; and forming the third electrode in the second region, andwherein a thickness of the third electrode in the second region is lessthan a thickness of the third electrode in the third region.
 12. Themethod of claim 1, wherein the third electrode is formed thicker thanthe second electrode.
 13. The method of claim 1, wherein adhesion of thesecond electrode in the second region is lower than adhesion of thesecond electrode in the first and third regions.
 14. The method of claim1, wherein adhesion of the third electrode in the first and secondregions is lower than adhesion of the third electrode in the thirdregion.
 15. The method of claim 1, wherein the first auxiliary layercomprises at least one selected from the group consisting oftris(8-hydroxy-quinolinato)aluminum (Alq3), di-tungstentetra(hexahydropyrimidopyrimidine), fullerene, lithium fluoride (LiF),9,10-di(naphth-2-yl)anthracene (AND), and 8-hydroxyquinolinolato-lithium(Liq).
 16. The method of claim 1, wherein the second auxiliary layercomprises at least one selected from the group consisting ofN,N′-diphenyl-N,N′-bis(9-phenyl-9H-carbazol-3-yl)biphenyl-4,4′-diamine,N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine,2-(4-(9,10-di(naphthalene-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzo-[D]imidazole),4,4,4-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA),N,N′-bis(1-naphthyl)-N,N′-diphenyl[1,1′-biphenyl]-4,4′-diamine (α-NPD),and 4,4′-Bis[N-(3-methylphenyl)-N-phenylamino]biphenyl (TPD).
 17. Themethod of claim 1, wherein the metal for forming the second electrodeand the metal for forming the third electrode comprise magnesium (Mg).